[Android] A prototype of the interactive media notification.

content/public/browser/web_contents_observer.h

Index: content/public/browser/web_contents_observer.h
diff --git a/content/public/browser/web_contents_observer.h b/content/public/browser/web_contents_observer.h
index 47ce40591f928a6df6089ea12d630df7fe30a845..501b94efb0c95f2c5f357ab95e6d74740f66aabd 100644
--- a/content/public/browser/web_contents_observer.h
+++ b/content/public/browser/web_contents_observer.h
@@ -366,6 +366,10 @@ class CONTENT_EXPORT WebContentsObserver : public IPC::Listener,
   // Invoked when media is paused.
   virtual void MediaPaused() {}
 
+  // Invoked when media session has changed its state.
+  virtual void MediaSessionStateChanged(bool is_controllable,
+                                        bool is_suspended) {}
+
   // Invoked if an IPC message is coming from a specific RenderFrameHost.
   virtual bool OnMessageReceived(const IPC::Message& message,
                                  RenderFrameHost* render_frame_host);